For three years, Investigator Cassie Dewell has been on the hunt for a serial killer known as the Lizard King, whose hunting grounds are the highways and truck stops where runaways and prostitutes are most likely to vanish. Working for the Bakken County, North Dakota sheriff's department, Cassie has lured him and his truck to a depot. But her plan goes horribly wrong, and consequently she loses her job. At the same time, Kyle Westergaard, a troubled kid whom Cassie has taken under her wing, has disappeared after telling people that he’s going off on a long-planned adventure. Kyle's grandmother begs Cassie to find him, and Cassie agrees --- all the while hunting the truck driver.